Technical Field
The present disclosure generally relates to the field of micro/nano integration technology, and particularly, to an Integrated Micro/nanogenerator and a method of fabricating the same.
Description of the Related Art
Micro-electro-mechanical system (MEMS) is, since being developed in the 1980s, a new-emerging and high technology involved in many realms and leading the development of microelectronics industry in the new century, and thus has attracted so many attentions in the worldwide. A plurality of branches such as optical micro-electro-mechanical system (Optical MEMS), radio-frequency micro-electro-mechanical system (RF MEMS), biomedical micro-electro-mechanical system (Bio-Medical MEMS) and traditional micro-electro-mechanical system (Physical MEMS) and the like have been booming and growing, and it is predicted that the MEMS industry will rapidly grows at a rate of 9.7% from 2011 to 2016 and will reach up to a global gross product of $12 billion by 2016. However, the above-mentioned MEMS systems and devices are required to be powered, while conventional power modules generally are large in size and difficult in integration machining, which limits the rapid development of MEMS industry. With a further reduction in size of micro-electro-mechanical systems, especially with the development of nano-electro-mechanical system (NEMS), it is extremely urgent to solve the problem of reliably supplying power for miniaturized devices and systems, particularly for micro-scale and nano-scale devices and systems.
A piezoelectric nanogenerator, in which zinc oxide nanowires are used to convert mechanical energy into electrical power, was successfully achieved by the group led by Professor Zhong-Lin WANG in the Georgia Institute of Technology of U.S.A in 2006 [Zhonglin WANG, et al. Science, vol. 312, pp. 5771, 2006; Xudong WANG, et al. Science, vol. 316, pp. 5821, 2007; Yong QIN, et al. Nature, vol. 451, pp. 7180, 2008]. Subsequently, many structures and many piezoelectric materials have been proposed to fabricate nanogenerators, but they are classified in mechanism into piezoelectric type nanogenerators [Guang ZHU, et al. Nanogenerator and Method of Fabricating the Same, Chinese invention patent application No. 201210116881.4; Mengke LI, et al. Nanogenerator, Chinese invention patent application No. 200910188057.8; Zhonglin WANG, et al. Nanogenerator, Nanogenerator Assembly and Self-Powered System Thereof, Chinese invention patent application No. 201210142387]. The piezoelectric nanogenerator technologies have been ripen and are applied in some industries; the piezoelectric materials such as zinc oxide nanowires and the like, however, are generally manufactured by a Bottom-Up growth process with low yield, poor uniformity and low output; and the devices have poor fatigue resistance and short service life due to frangibility of the nanowire material itself.
In January, 2012, the Professor Zhonglin Wang's study group proposed a new triboelectrification-based nanogenerator, in which PET and Kapton materials are used as the triboelectric pair to generate charges through the contact-mode triboelectrification effect, and the output power is generated during its periodic pressing/releasing process. [Feng-Ru FAN, et al. Nano Energy, vol. 1, pp. 328, 2012]. In March, 2012, the group led by Professor Zhonglin WANG proposed an improved structure for the triboelectrification-based nanogenerator, in which PDMS material, in place of the Kapton material, is used to induce charges by friction with the PET materials, and a micro-scale pyramid array structure is manufactured on a surface of the PDMS so as to increase its roughness, thereby increasing output [Feng-Ru FAN, et al. Nano Letters, vol. 12, pp. 3109, 2012]. The above-mentioned structures, although of different from each other in materials, are essentially those in which friction are made between surfaces of two layers of films, have the roughness which are only improved by the micro-scale structure, and have a maximal output voltage of 18V, which cannot meet power supply requirements of some micro-nano systems.